I was going down the road and heard a loud noise. Then car turned off. Went to a a complete stop. I'd open the hood to see if the belt pop off but it didn't. Got in the car and turn it on. It turn on but when I'd put it in gear in reverse, I'd heard that loud pop noise again. Then put it to drive and the car wouldn't go forward or reverse
My car has 330000 miles.
My car has an automatic transmission.
You have had a catastrophic failure of the rear end, transmission, or a component at a wheel. This is a major repair that will first require someone to determine which component failed. To figure this out, I would lift the car into the air on a rack, put it in gear, and give it some throttle. I would then follow the noise to find what failed. It is possible you can look underneath and the failure will be obvious, but most likely, it will require following the noise.
Locating a noise like this can be dangerous without a rack to lift the wheels off the ground. If you decide to chase the noise yourself, be sure to stay clear of the wheels that could lurch forward suddenly. If it is the transmission or rear end, you will need to be under the car to be sure where the noise is coming from, and this is not advisable.
This is most likely a large repair that could exceed the value of the car. Of course, how much you value it is what’s important. You will need to determine this for yourself.
If you need some help with this, I recommend booking an appointment with a certified technician, such as one from YourMechanic, to help diagnose the noise when your car changes gear.